Oxyalkylated-carbonated phenates in lubricating oils



United States Patent i 2,989,466 OXYALKYLATEDFCARBONATED PHENATES INLUBRICATING OILS Andrew Doyle Abbott, Ross, Califi, assignor toCalifornia Research Corporation, San Francisco, Calif., a corporation ofDelaware No Drawing. Filed Oct. 6, 1959, Ser. No. 844,621 4 Claims. (Cl.252-417) This invention pertains to improved metal salts of alkylphenolsparticularly useful as lubricating oil additives; more particularly,this invention is directed to lubricating oil compositions havingincorporated therein as detergents certain particular modified metalalkylphenates.

This application is a continuation-in-part of patent application SerialNo. 685,07 3, filed September 20, 1957, and now abandoned.

It is well known that metal salts of alkylphenols are useful asdetergents and as acid neutralizers in lubricating oils compositions.Because of their excellent detergent characteristics and acidneutralizing properties, lubricating oils containing metal phenates havebeen partcularly effective in heavy duty oils used for lubricating highspeed diesel and gasoline engines.

crankcase lubricants in internal combustion engines are exposed toextremely severe conditions of operation, particularly in diesel engineservice, wherein the lubrieating oil compositions encounter temperaturesas high as 650 F. and higher, and pressures of 1000 psi and higher.Under such conditions of operation, the lubricating oil compositionshave a tendency to deteriorate, forming gummy deposits on the pistonrings, the piston lands, and the skirts of the pistons. Such depositformation has been inhibited by the use of metal phenates as detergents.

The effectiveness of the metal salts of alkylphenols as detergents ismodified by storage conditions, particularly when lubricating oilcompositions containing such metal alkyl phenates are exposed to water.Water may become admixed with the lubricating oil composition simply bythe normal breathing of the container in which the lubricating oilcompositions are stored. That is,

during changes in temperature, the air may be sucked into the bulkcontainers, and the water vapor in the air will condense in the oilcontainer, gradually becoming admixed with the oil. This watersensitivity of alkyl phenates has been reduced by known treatment ofalkyl phenates with carbon dioxide; that is, when metal phenates aretreated with carbon dioxide, this water sensitivity is minimized.However, even though the water effect on phenates has been reduced bythis carbon dioxide treatment, such lubricating oil compositions stillbreak down prematurely.

' It is not only water sensitivity which effects the benefi-cialcharacteristics of metal salts of alkylphenols in lubricating oilcompositions. Other factors which must be considered are color stabilityand viscosity stability during storage, and the characteristic whichpermits a metal phenate to blend in an-oil containing other additiveswithout forming an undesirable .haze.

j Therefore, it is an object of the present invention to preparelubricating oil compositions having incorporated therein a storagestable metal salt of an alkylphenol.

.In accordance with the present invention, it has been discovered that.improved lubricating oil compositions areobtained by incorporatingtherein oxylakylated-carbonated metal alkyl phenates. Thus, thelubricating oil 7 Patented June 20, 1961 use of lighter oils reduces theoverall mileage obtainable by such a composition. However, by the use ofthe oxylkylated-carbonated metal phenates of the present invention,heavier base oils can be used in the blending of lubricating oilcompositions useful for internal conibustion engines. Therefore, sinceheavier base oils give better oil mileage in engine operation, the oilcompositions described herein give better oil mileage than thatpreviously obtainable With untreated metal alkyl phenates.

As used herein, the term "oxyalkylated-carbonated metal phenate meansthe product obtained by first reacting a metal salt of an alkyl .phenol,including sulfurized metal salts of alkyl phenols, with an alkyleneoxide, followed by reaction with carbon dioxide. Alkylene oxidescondense with active hydrogen atoms of the phenates, and the subsequentreaction with carbon dioxide converts the phenate metal to a partialbicarbonate. The reaction products thus prepared are not described inthe art wherein it is known to alkylate an alkyl phenol'with ethyleneoxide, then form the salt of the thus alklated product, using thistmcarbonated product as a lubricating oil additive. It is not meantherein to describe any theory in the formation ofoxyalkylated-carbonated metal phenates which are described herein asuseful additives for lubricating oil compositions.

The alkylene oxides which are useful herein in the reaction with metalsalts of alkyl phenols are the alkylene oxides containing from 2 to 3 ormore carbon atoms,

preferably 2 to 3, and as ethylene oxide, propylene oxide, etc., asexemplified by the formulas: I

OH2-CH2 CHE-037C112 MAOL Mi ly wherein A is an essentially hydrocarbonaromatic radical, such as a naphthalene radical and a benzene radical,preferably a benzene radical; R is a cyclic, straight-chain orbranched-chain, saturated or unsaturated, essentially hydrocarbonradical (e,g., an aliphatic radical) having from 4 to 30 carbon atoms, 0represents oxygen, a is a number having a value from 1 to 5, M is apolyvalent metal, x is a number from 1 to the valence of the metal M,and y is a number equal to the difference of x and said valence.

Examples of suitable hydrocarbonaceous radicals (that is R radicalsin'the above formula) include alkyl radicals such as butyl, hexyl,octy-l, decyl, dodecyl, hexadecyl, eicosyl, triacontyl radicals, etc.;radicals derived from petroleum hydrocarbons, such as white oil, wax,olefin polymers (e.g., polypropylene and polybutylene), etc.; arylradicals such as phenyl, naphthyl, etc; aralkyl radicals such asphenyloctyl, phenyldecyl, phenyloctadecyl,

etc.; alkaryl radicals such as amylphenyl, cetylphenyl,

; etc.

Examples of the metal M include lead and the metals of Group II ofMendeleefs Periodic Table, particularly the alkaline earth metals, forexample, calcium.

In the lubricating oil compositions of this invention, it isparticularly preferred that the metal salts of the so-called basicsulfurized metal alkyl phenatm are used in the reaction withoxyalkylenes and carbon dioxide. Thus, as used herein, the term basicsulfurized metal phenates refers to sulfurized metal phenates whereinthe mol ratio of the metal to phenol derivative is greater than that ofthe normal sulfurized metal phenates. That is, in the normal sulfurizedcalcium phenates, the mol ratio of metals to alkyl phenol is 1:2.

In the lubricating oil compositions herein containingoxyalkylated-carbonated metal phenates, it is preferred that in thefinal product the average mol ratio of alkylene oxide to metal alkylphenate (based on the metal) has a value no greater than about 4 (i.e.,a maximum value of about 4) with a minimum value of about 0.05. It ispreferred that the average mol ratio value is from 0.3

. In the carbonation step in the preparation of the phenates of thisinvention, it is preferred that the average mol ratio of carbon dioxideto oxyalkylated metal alkyl phenate ranges from 0.1 to 1.0.

The metal salts of alkyl phenols as used herein include the sulfurizedmetal salts of alkyl phenols such as described in US. Patents Nos.2,680,096 and 2,680,097.

Suitable base oils useful in the composition of this invention include awide variety of lubricating oils such as naphthenic base, parafiin base,and mixed base mineral oils, other hydrocarbon lubricants, e.g.,lubricating oils derived from coal products and synthetic oils, e.g.,alkylene polymers (such as polymers of propylene, butylene, etc.)alkylene oxide type polymers, dicarboxylic acid esters, liquid esters ofacids of phosphorus and silicon, polysiloxanes, etc. Synthetic oils ofthe alkylene oxide type polymers which may be used include thoseexemplified by the alkylene oxide polymers and derivatives, includingalkylene oxide polymers prepared by polymerizing alkylene oxides, e.g.,propylene oxide, in the presence of water or alcohols (e.g., ethylalcohol, and esters of alkylene oxide type polymers).

Synthetic oils of the dicarboxylic acid ester type include those whichare prepared by esterifying such dicarboxylic acids as adipic acid,azelaic acid, suberic acid, sebacic acid, alkenyl succinic acid, fumaricacid, maleic acid, etc., with alcohols such as butyl alcohol, hexyl"alcohol, 2ethyl hexyl alcohol, dodecyl alcohol, etc.

Examples of dicarboxylic acid synthetic oils include dibutyl adipate,dihexyl adipate, di-Z-ethyl-hexyl sebacate, etc.

Synthetic oils of the alkyl benzene type include those which areprepared by alkylating benzene (e.g., dodecyl benzene, etc.). Syntheticoils of the type of the liquid esters of silicon and polysiloxanesinclude those exemplified by tetra (2-ethyl hexyl) silicate,polymethylphenyl siloxane, polymethyl siloxane, etc.

The oxyalkylated-carbonated metal alkyl phenates herein may be used inlubricating oil compositions in amounts sufficient to impart improveddetergency characteristics, that is, in amounts of about 0.1% to about25%, by weight, to as high as 50%, preferably 0.5% to 5%, by weight.Their unique physical characteristics make the phenates particularlysuitable for lubricating oil concentrates containing up to 75% ofphenate.

The immediate examples hereinbelow describe a method of preparing basicsulfurized metal phenates which are preferably used according to thispresent invention in the further reaction with alkylene oxides of carbondioxide.

Example 1.--Preparation of alkyl phenol A mixture consisting of 300parts by weight of phenol, 555 parts by weight of olefin polymers havingaverage 4 molecular weights of 170, and 45 parts by weight ofacidtreated clay was heated at 300 F. for a period of 12 hours, afterwhich the mixture was filtered. The remaining reaction was heated to 530F. to remove unreacted phenol, olefin polymers, and low molecular weightalkylphenols.

Example 2.Preparation of sulfurized metal alkyl phenate A mixture of 600parts, by weight, of an alkylphenol having a boiling range of 560 F. to700 F., parts, by weight, of calcium hydroxide, 55 parts, by weight, ofsulfur, and 300 parts, by weight, of ethylene glycol was heated at 300F. with agitation at an absolute Pressure of 300 mm. of mercury. Afterthe water of reaction had been distilled off, the pressure was reducedto 60 mm. of mercury and the temperature raised to 380 F., at whichtemperature and pressure the ethylene glycol was removed. During theperiod when the glycol was being removed, 400 parts, by weight, ofpetroleum lubricating oil were added. When substantially all of theethylene glycol had been removed, the mixture was cooled and 200 parts,by weight, of a petroleum thinner were added and the mixture wasfiltered. The filtrate was heated at reduced pressure to remove thepetroleum thinner. The final lubricating oil composition contained 2.85%sulfur and 5,63% calcium; the basic sulfurized calcium alkyl phenatecontaining 92% more calcium than that present in the correspondingnormal alkyl phenate.

Example 3.Preparati0n of sulfurized metal alkyl phenate A mixture of 300parts, by weight, of an alkylphenol having a hydroxyl number of 155, 40parts, by weight, of calcium hydroxide, 19 parts, by weight, of sulfur,50 parts, by weight, of ethylene glycol and 200 parts, by weight, ofpetroleum lubricating oil was slowly heated up to a temperature of 375F. at an absolute pressure of 60 mm. of mercury. The temperature of 375F. was maintained for 3 hours to remove substantially all of theethylene glycol, after which time the reaction mixture was filtered. Thelubricating oil solution of normal sulfurized calcium alkyl phenatecontained 3.83% calcium and 1.67% sulfur.

Example 4--Preparati0n of sulfurized metal alkyl phenate A mixture of110 pounds (0.325 mol) of an alkylphenol having a hydroxyl number of 166(and wherein the alkyl radical was derived from propylene polymershaving an average of 12 carbon atoms), 24 pounds (0.325 mol) of hydratedlime, and 12.5 pounds (0.389 mol) of sulfur was heated to F. withconstant agitation until a uniform mixture was obtained. The mixture wasthen heated to 260 F. at 500 mm. of mercury absdlute, after which 45pounds (0.725 mol) of ethylene glycol and 106 pounds of Mid-Continentneutral oil having a viscosity of about 100 SSU at 100 F. (which hadbeen previously heated to about 225 F.) were added. The water ofreaction was removed and the heating was continued. The ethylene glycolwas distilled oil by heating to 380 F. at 45 mm. of mercury.

Example 5-Preparation of oxyalkylaIed-carbonated sulfurized metalphenate STEP A Ethylene oxide was charged to the final reaction mix tureof Example 4 hereinabove at 300 F. The ethylene oxide was injected atthe bottom of the reaction vessel so that the ethylene oxide pressurenever exceeded 5 p.s.i.g. until 6.5 pounds (0.147 mol) of ethylene oxidehad been added to the reaction mixture during a period of 25 minutes.Moderate cooling was required to maintain the reaction temperature at300 F. After all of the ethylene oxide had been introduced, the reactionwas stirred for an additional 30 minutes, followed by purging withnitrogen to remove any excess ethylene oxide; that is, the

unreacted ethylene oxide.

STEP B The reaction vessel was then pressured to 75 p.s.i.g

proximately 12 pounds (0.252 mol) of carbon dioxide were introduced intothe reaction. The whole reaction mixture was maintained at a temperatureof 300 F. under 75 p.s.i.g. carbon dioxide pressure with constantagitation for a period of one hour.

Filter aid (e.g., Hyflo-Super-Cel) was added to the reaction mixture andthe product was filtered through a filter-press." Table I hereinbelowsets-forth the analysis ofai the products obtained.

Table I hereinbelow presents analyticalidata obtained by'ana'lysi's ofthe products of Examples 4 and 5 hereinabove.

- TABLE II Unmodified I Finished Phenate Product of Produce of Productof Step A Step B Example 4 Percent Calcium 4. 25 4. 19 4. 10 PercentSulfur 2. 49 2. 40 aseN m Hme KO lz-L 112 1 106 Percent 4 2.3 PercentSulfated Ash 14.1 l3. 9 13.5 ASTM Color, Dilute 3 2. 2. 5 Viscosity,SSU' For the purpose of ascertaining that an oxyalkylated phenate wasobtained in-Step A of Example 5 hereinabove tl1e product wasfractionated by precipitation with acetone. The phenate was thenpurified by reprecipitating several times from acetone. The resultingsolid oxyalkylated .alkylphenate contained 13.1% calcium and 5.5%

"sulfur; and the color .was chalky white. Upon analysis "with .theinfrared spectrometer; it was ascertained that an oxyalkylated phenatehad been obtained.

The data of Column 2 of Table I hereinabove markedly show theundesirable viscosity effects obtained by the oxyalkylation of phenates.On the other hand, the viscosity characteristics of the finishedoxyalkylated-carbom' ated phenate as shown in Column 3 of Table I weresimilar to those of the unmodified original phenate.

Table II hereinbelow presents data which illustrate further theundesirable viscosity efiects obtained by oxyalkylation only of metalphenates. A sulfurized metal alkyl phenate was oxyalkylated withethylene oxide similarly as described in Step A of Example 5hereinabove.

TABLE H Unmodlfied Phe- Oxyalkylated Phenates nate Mol Ratio, EthyleneOxide/Ca 0.0 0.55 0.78 1.06 Viscosity, SSU:

1 Calcium of the calcium phenate.

Table III hereinbelow summarizes reaction conditions and analytical dataof further preparations of oxyalkylated-carbonated sulfurized metalalkyl phenates.

The sulfurized metal alkyl phenate (noted in the tables as reactantSMAP) was a 45% petroleum oil solution of a sulfurized calcium alkylphenate containing 4.21%, by weight, calcium, and 2.72% sulfur, andwherein the alkyl radical was derived from propylene polymers having anaverage of 12 carbon atoms.

TABLE III Experiment No 1 2 3 4 5 6 -I. Reaetants (STEP A):

BMAP (Wt. Percent) 100 94.7 94.9' 92. 9 97.5 98.1 Ethylene Oxide (Wt.Percent) 5. 3 5. 1 7. 1 2. 5 l. 3 Mel Ratio, SMAP Ethyu lene Oxide 1.211.17 1.6 0.5 0.3

' Reactionlemp F 380 300 350 -350 200 Percent Calcium. 4. 21 3. 99 4. 043. 95 4.11 3. 8 'Percent'Sulfur- 2.72 8.36 2. 58- 2.51 2.57 2.8Viscosity (SSU): 1 100]? 2,690 5,316 5,942 5,645 4,267 4,060

210! 13 16 V 18 17 166 160 II. Reactants (STEP B) (Car- 'bonation Step):7 7

Pressure Temperature, F 380 300 350 350 200 III. Analysis Final Product:

, Percent Calcium 3. 98 4.03 3. 97 4.02 3.77 Percent Sulfur. 2. 46. 2.30 2.35 2.68 Viscosity (SSU) I 100 F 1, 428 1, 870 1, 572 1, 708 2, 998210 F 81 y 84 94 134 Atmos. 3 2.5 Hg.

described as follows:

(a) The engine used'for the L-1 test was a Caterpillar single-cylinder,5%" bore diesel engine; it was run for hours at 100 r.-p.m. at a load of19.8 brake horsepower, oil temperature of F. to F., jacket temperatureof F. to F., using a fuel containing 1% sulfur. (b) The engine used inthe Ir-4 test was a stock Chevrolet engine, wherein the normal Babbittbearings where replaced with copper-lead bearing inserts, which wereweighed before being assemblied in the engine. The Chevrolet engine wasoperated at 3150 r.p.m., the engine jacket temperature was maintained at200 F., the crankcase oil temperature was maintained at 280 F., and theengine was operated for a period of 52 hours, at which time the bearinginserts were weighed.

(0) The engine used for the l-G test was a Caterpillar single-cylinderengine having a 5%" bore and a 6%" stroke; operating at 1800 r.p.m. with42 brake horsepower; an oil temperature of 205 F.; an inlet airtemperature of 255 F.; supercharged to 53 inches of mercury absolute;for a period of 120 hours, using a fuel with a minimum sulfur content of0.35%.

The groove deposit ratings noted in Table II as GD Rating refers to theamount of deposit in the top ring groove as a percent of the totalpossible. That is, a rating of 0 means that there was no deposit in thegroove, and a rating of 100 means that the groove was completely filledwith deposit.

The sulfonate used in the oil composition was a calcium petroleumsulfonate.

The sulfide was a sulfurized diparatlin sulfide.

The thiophosphate was a zinc salt of a mixed diester of dithiophosphoricacid, wherein one of the ester radicals was derived from butyl alcoholand the other ester radical was derived from methylisobutylcarbinol.

Phenate A was a sulfurized calcium alkyl phenate as described in Example4, hereinabove.

Phenate B was an oxyethylated-carbonated sulfurized calcium alkylphenate as described in Example 5 hereinabove.

TABLE IV Oil Composition mM. g3 p [K Whole Engine Test Bearing GD TestDuration Phenate- Weight Rating (hours) Sulfonate Thiophos- Percent Lossphate Sulfide (mgs.) A B l-G 120 as s1 s L-l 120 17.5 28.6 7 0.35 i 12120 17. 5 28. 5 7 0.35 1 I-4 62 7 16 6 0. 25 846 oil composition.

an alkylphenol, followed by reaction with from 0.1 mol to 1 mol ofcarbon dioxide per mol of metal alkyl phenate, wherein said alkylphenolcontains from 4 to 30 carbon atoms in the alkyl radical and said metalis a metal selected from the group consisting of lead and the metals ofGroup II of Mendeleefs Periodic Table.

2. A lubricating oil composition comprising an oil of lubricatingviscosity, and from 0.1% to 25%, by weight,

of an oxyalkylated-carbonated sulfurized metal alkyl phenate, whereinsaid oxyalkylated-carbonated sulfurized metal alkyl phenate is obtainedby reacting from 0.05

mol to 4 mol of an alkylene oxide per mol of sulfurized 'metal alkylphenate, with subsequent reaction with 0.1

mol to 1 mol of carbon dioxide per mol of sulfurized metal phenate,wherein said alkyl radical of said phenate contains from 4 to 30 carbonatoms and said metal is a metal selected from the group consisting oflead and the metals of Group II of Mendeleefs Periodic Table.

' 3. A lubricating oil composition comprising an oil of lubricatingviscosity, and from 0.5% to 5%, by weight,

of an oxyalkylated-carbonated sulfurized metal alkyl phenate, whereinsaid oxyalkylated-carbonated sulfurized metal alkyl phenate is obtainedby reacting from 0.05 mol to 4 mol of an alkylene oxide per mol ofsulfurized metal alkyl phenate, with subsequent reaction with 0.1 mol to1 mol of carbon dioxide per mol of sulfurized metal phenate, whereinsaid alkyl radical of said phenate contains from 4 to 30 carbon atomsand said metal is a metal selected from the group consisting of lead andthe metals of Group II of Mendeleefs Periodic Table.

4. The lubricating oil composition of claim 1, wherein said metal is ametal of Group II of Mendeleefs Periodic Table, and said alkylene oxideis ethylene oxide.

References Cited in the file of this patent UNITED STATES PATENTS2,402,448 Richards June 18, 1946 2,406,041 Schneider et al Aug. 20, 19462,659,696 Netf Nov. 17, 1953 2,680,096 Walker et a1. June 1, 19542,736,701 Neff Feb. 28, 1956 2,762,774 Popkin Sept. 11, 1956 2,781,403Kane et a1 Feb. 12, 1957

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF AN OILOF LUBRICATING VISCOSITY, AND, IN AN AMOUNT SUFFICIENT TO IMPARTDETERGENCY CHARACTERISTICS TO SAID LUBRICATING OIL COMPOSITION OF ANOXYALKYLATEDCARBONATED METAL ALKYL PHENATE, WHEREIN SAIDOXYALKYLATED-CARBONATED METAL ALKYL PHENATE IS OBTAINED BY REACTING, PERMOL OF METAL SALT OF ALKYLPHENOL, FROM 0.05 TO ABOUT 4 MOLS OF ANALKYLENE OXIDE WITH A METAL SALT OF AN ALKYLPHENOL, FOLLOWED BY REACTIONWITH FROM 0.1 MOL TO 1 MOL OF CARBON DIOXIDE PER MOL OF METAL ALKYLPHENATE, WHEREIN SAID ALKYLPHENOL CONTAINS FROM 4 TO 30 CARBON ATOMS INTHE ALKYL RADICAL AND SAID METAL IS A METAL SELECTED FROM THE GROUPCONSISTING OF LEAD AND THE METALS OF GROUP II OF MENDELEEF''S PERIODICTABLE.